Offer or Advance Acceptance?

When a seller puts a car up on an online auction site and announces it will take the highest bid for the car, is that on offer to sell, an invitation for bid, or an advance acceptance of the as-yet-to-be-made highest offer?

Well, it doesn't matter in Germany, because the seller's statement is a declaration of will by the seller which, after a reciprocal declaration of will by the buyer, results in a contract.  Thus, in BGH NJW, where a buyer's 26,350 DM bid for a new Volkswagen Passat, made eight seconds before the auction closed, was the high bid, the seller was bound to seller the car, regardless of whether it claimed it intended to or not.

[Frank Snyder]